The etiology of interstitial cystitis (IC) is an enigma. The central thesis of this application is that buried bacterial genomes in the form of cell wall-deficient/defective bacteria (CWDB) or otherwise aberrant bacteria (nutritionally deficient) which have not been cultured by routine methodology may be important bacteriologic entities overlooked in IC. Derangements of host protective mechanisms and chronic use of wall-inhibiting antibiotics may allow bacteria entering body fluids and tissues to be partially or completely degraded of their cell walls, but otherwise unchanged. Without their highly immunogenic cell walls, aberrant bacteria could avoid recognition by the host, enter host cells and multiply within them. It is possible that this type of bacterial persistence could occur in IC. A prominent feature in IC is the loss of the mucin layer of the transitional cell epithelium of the urinary bladder. Persisting bacteria may contribute directly or indirectly (via their products or by immune mechanisms involving bacterial antigens) to the patbology of IC. We are proposing to search for aberrant bacteria in the urine of 60 patients with IC by special culture techniques in an effort to cultivate CWDB. We shall also culture for Mycoplasma species and search for Chlamydia trachomatis in the urine sediments using a fluorescent monoclonal antibody to the group antigen of Chlamydia. Additionally, we shall utilize the polymerase chain reaction (PCR) employing optimized bacterial primers with thin sections of biopsied bladder lesions from IC patients. Demonstrating bacteria, whether by culture or PCR will result in an attempt to completely classify the organisms using hybridization with specific oligonucleotides that are radiolabelled. Analyses to detect antibacterial antibodies from the sera of IC patients and from their urine will be assayed by western blots using lysates of organisms isolated or from various potential bacterial pathogens (Escherichia coli, Pseudomonas aeruginosa, Streptococcus faecalis and Staphylococcus saprophyticus). We will use these sources of genomic DNA to optimize the PCR; DNA from affected tissue and from peripheral mononuclear leukocytes of normal controls will be utilized. The initial screen will involve use of universal PCR primers to detect PCR products by ethidium bromide staining, presence of radiolabelled dCTP and radiolabelling of one of the primers. Positive bacterial findings could lead to improved diagnosis and treatment of patients with IC.